Fish Surveys

Published

May 7, 2024

Metadata

Figure 1: Location of fish surveys
Table 1: Summary of work by island and exposure
Number of fish surveys per location, habitat, and exposure
Exposure Strata # Sites # Transects # Reels Surveyed distance (m)
Fanna
Forereef Leeward 2 1 2 6 150
Forereef Windward 2 5 10 30 750
Total — — 6 12 36 900
Helen
Backreef Lagoon 1 1 2 6 150
Patchreef Lagoon 2 3 6 18 450
Forereef Leeward 2 6 12 36 900
Forereef Windward 2 5 10 30 750
Total — — 15 30 90 2250
Merir
Forereef Leeward 2 3 6 18 450
Forereef Windward 2 4 8 24 600
Total — — 7 14 42 1050
Pulo Anna
Forereef Leeward 2 2 4 12 300
Forereef Windward 2 2 4 12 300
Total — — 4 8 24 600
Sonsorol
Forereef Leeward 2 4 8 24 600
Forereef Windward 2 3 6 18 450
Total — — 7 14 42 1050
Tobi
Forereef Leeward 2 5 10 30 750
Forereef Windward 2 1 2 6 150
Total — — 6 12 36 900
Grand total — — 45 90 270 6750

QA/QC

Taxa

Observations

Expedition Summary

Table 2: Summary of results
Average species richness, abundance, and biomass
Sites # Transects # Reels # Taxa Abundance (ind/m2) Biomass (g/m2)
By exposure
Lagoon 4 8 24 67.88 8.04 (7.53) 191.03 (73.56)
Leeward 21 42 126 67.29 9.64 (6.72) 636.46 (264.39)
Windward 20 40 120 72.88 12.94 (8.39) 857.42 (570.15)
By strata
Deep 44 45 135 69.44 10.42 (7.46) 799.14 (540.27)
Shallow 44 45 135 70.20 11.51 (8.00) 591.00 (336.92)
Overall
Total 45 90 270 69.82 10.96 (7.71) 695.07 (459.76)

Location summary

Table 3: Summary of results by island and depth strata.
Average species richness, abundance, and biomass by location
Sites # Transects # Reels # Taxa Abundance (ind/m2) Biomass (g/m2)
Fanna
Deep 6 6 18 77.50 13.76 751.83
Shallow 6 6 18 60.83 14.36 328.81
Overall — 12 36 69 14 540
Helen
Deep 14 15 45 67.80 6.82 696.49
Shallow 14 15 45 74.87 9.73 646.62
Overall — 30 90 71 8 672
Merir
Deep 7 7 21 67.57 6.33 875.68
Shallow 7 7 21 73.43 5.68 697.21
Overall — 14 42 70 6 786
Pulo Anna
Deep 4 4 12 61.25 17.72 1431.37
Shallow 4 4 12 67.50 10.43 756.46
Overall — 8 24 64 14 1094
Sonsorol
Deep 7 7 21 72.57 17.38 552.88
Shallow 7 7 21 64.00 17.22 422.41
Overall — 14 42 68 17 488
Tobi
Deep 6 6 18 69.50 7.87 879.63
Shallow 6 6 18 73.17 13.96 676.63
Overall — 12 36 71 11 778

Analyses

Diversity

Figure 2: Number of species by order and family
Figure 3: Species richnnes by island
Table 4: Results of Adonis model for univariate analysis of fish species richness
Results of Adonis model for univariate analysis of fish species richness
df SumOfSqs R2 statistic p.value
depth_strata 1 17.187 0.001 0.134 0.688
location 5 700.063 0.061 1.095 0.348
exposure 1 865.000 0.075 6.763 0.014
habitat 1 17.074 0.001 0.133 0.712
diver 1 18.771 0.002 0.147 0.737
Residual 79 10104.930 0.877 NA NA
Total 89 11527.156 1.000 NA NA
Figure 4: Species richnnes by exposure by island

Abundance

Figure 5: Fish abundance by island
Table 5: Results of Adonis model for univariate analysis of fish abundance
Results of Adonis model for univariate analysis of fish abundance
df SumOfSqs R2 statistic p.value
depth_strata 1 29.318 0.006 0.767 0.381
location 5 1245.230 0.235 6.515 0.001
exposure 1 229.449 0.043 6.003 0.021
habitat 1 2.019 0.000 0.053 0.805
diver 1 695.530 0.132 18.196 0.001
Residual 79 3019.706 0.571 NA NA
Total 89 5289.048 1.000 NA NA
Figure 6: Abundance by exposure by diver
Figure 7: Abundance by exposure by island

Biomass

Figure 8: Fish biomass (g/m2) by island
Table 6: Results of Adonis model for univariate analysis of fish biomass
Results of Adonis model for univariate analysis of fish biomass
df SumOfSqs R2 statistic p.value
diver 1 281913.07 0.015 2.014 0.170
depth_strata 1 965942.72 0.051 6.899 0.010
habitat 1 16539.82 0.001 0.118 0.709
exposure 1 1580881.99 0.084 11.291 0.004
location 5 3247391.55 0.173 4.639 0.003
Residual 79 11060545.73 0.588 NA NA
Total 89 18812734.31 1.000 NA NA

By depth

Figure 9: Biomass by depth strata by island

By exposure

Figure 10: Biomass by exposure by island
Table 7: Summary of results by island and exposure
Average species richness, abundance, and biomass by location and exposure
Sites # Transects # Reels # Taxa Abundance (ind/m2) Biomass (g/m2)
Fanna
Leeward 1 2 6 69.50 10.40 812.14
Windward 5 10 30 69.10 14.79 485.95
Helen
Lagoon 4 8 24 67.88 8.04 191.03
Leeward 6 12 36 66.42 6.01 544.84
Windward 5 10 30 80.00 11.18 1208.03
Merir
Leeward 3 6 18 68.17 5.40 867.84
Windward 4 8 24 72.25 6.46 725.40
Pulo Anna
Leeward 2 4 12 62.00 13.51 667.86
Windward 2 4 12 66.75 14.64 1519.97
Sonsorol
Leeward 4 8 24 65.50 13.97 399.07
Windward 3 6 18 72.00 21.74 605.73
Tobi
Leeward 5 10 30 70.90 11.36 749.79
Windward 1 2 6 73.50 8.67 919.82

By family

Figure 11: Biomass by family
Figure 12: Biomass by family and depth strata

By trophic group

Figure 13: Biomass by trophic group

By species

Figure 14: Frequency, abundance, and biomass by species
Table 8: Top 30 fish species
Top 30 fish species with highest contribution to overall fish biomass
Trophic/Family Taxon Min length (cm) Mean length (cm) Max length (cm) Frequency (% stations) Abundance (ind/m2) Biomass (g/m2)
Planktivore
Fusilier Pterocaesio tile 15.5 21.0775 28.5 65.5556 0.5035 100.6940
Surgeonfish Naso hexacanthus 35.0 49.1292 60.0 60.0000 0.0324 78.2022
Fusilier Caesio teres 12.0 22.8765 32.5 48.8889 0.1561 34.2468
Snapper Macolor macularis 10.0 42.7249 60.0 80.0000 0.0191 28.5944
Fusilier Pterocaesio randalli 16.0 19.2286 25.0 24.4444 0.2209 24.4358
Fusilier Caesio lunaris 20.0 23.8846 32.5 30.0000 0.0636 24.2721
Surgeonfish Naso vlamingii 20.0 37.5598 55.0 73.3333 0.0146 18.4607
Fusilier Pterocaesio pisang 9.5 14.1216 17.5 21.1111 0.3037 14.7459
Surgeonfish Naso annulatus 50.0 62.2581 76.5 22.2222 0.0025 12.2742
Surgeonfish Acanthurus thompsoni 7.5 16.6341 23.0 73.3333 0.1142 12.0412
Damselfish Lepidozygus tapeinosoma 4.0 7.2604 10.5 25.5556 1.2689 11.1905
Fusilier Pterocaesio tessellata 14.0 19.2045 25.0 15.5556 0.0720 10.9723
Damselfish Chromis ternatensis 2.0 6.5685 10.5 74.4444 0.8750 10.5212
Soldierfish Myripristis kuntee 13.0 16.5206 21.0 63.3333 0.0580 8.1460
Soldierfish Myripristis berndti 7.0 22.2576 29.0 56.6667 0.0369 7.3766
Triggerfish Odonus niger 16.0 23.2586 28.0 15.5556 0.0203 6.8287
Soldierfish Myripristis vittata 8.0 16.1556 18.0 46.6667 0.0737 6.8130
Damselfish Pycnochromis margaritifer 2.5 4.9610 5.5 87.7778 3.0841 6.0863
Fusilier Caesio caerulaurea 13.5 21.5833 28.0 7.7778 0.0295 5.3067
Snapper Macolor niger 28.0 44.1800 60.0 12.2222 0.0029 4.6755
Top-predator
Jack Caranx sexfasciatus 52.5 56.2500 62.5 4.4444 0.0049 13.9544
Jack Caranx papuensis 35.0 43.3333 55.0 2.2222 0.0167 13.4909
Jack Elagatis bipinnulata 30.0 56.3421 67.5 13.3333 0.0136 12.6955
Snapper Lutjanus bohar 8.0 40.4231 80.0 68.8889 0.0093 10.6575
Jack Caranx melampygus 22.0 44.1250 85.0 44.4444 0.0044 5.9582
Snapper Lutjanus gibbus 25.0 33.3396 41.0 32.2222 0.0110 4.9626
Herbivore
Parrotfish Scarus rubroviolaceus 6.0 39.7792 65.0 54.4444 0.0053 7.6076
Parrotfish Chlorurus microrhinos 5.0 44.6389 65.0 35.5556 0.0036 5.7659
Chub Kyphosus cinerascens 13.0 32.3784 45.0 23.3333 0.0102 5.7253
Surgeonfish Naso unicornis 38.0 46.6667 58.0 15.5556 0.0026 5.2751

Community assemblages

Table 9: Fish assemblages Adonis model
Figure 15: Principal coordinates analysis
Table 10: Results of ANOVA on the ordination model